Question

A particle of mass m is moving along a circular path of radius r and F is the centripetal force acting on it. The work done by the centripetal force in moving it along a semicircular path is-

• A. zero
• B. F.pr
• C. 2Fr
• D. Fmr

Answer 1

The correct option is A zero

Centripetal force is always perpendicular to displacement $\overline{d}s$ Thus $F.ds=0$

Thus work done = $\int \overline{F}.\overline{d}s=0$